Involvement of P2X7 receptors in satellite glial cells of dorsal root ganglia in the BmK I -induced pain model of rats

Abstract

The P2X7 receptor (P2X7R) plays an important role in inflammatory and neuropathic pain. Our recent study indicated that activation of P2X7R in microglial cells of spinal cord contributes to the inflammatory pain induced by BmK I, the major active compound from Buthus martensi Karsch (BmK). In the present study, we further investigated whether P2X7R in satellite glial cells (SGCs) of dorsal root ganglion (DRG) is involved in the BmK I-induced pain in rats. The results found that the expression of P2X7R in SGCs was increased in the ipsilateral side of L4-L5 DRGs after intraplantar injection of BmK I. Moreover, the expression of an inflammatory cytokine IL-1β was increased in DRG after BmK I injection. Systemic administration of an inhibitor of P2X7R (A-438079) significantly inhibited both spontaneous and evoked nociceptive behaviors induced by BmK I. These results suggest that the P2X7R in SGCs of DRG might contribute to pain induced by toxins that sensitize peripheral sensory nerves.

Satellite Glial Cells: Morphology, functional heterogeneity, and role in pain

“…For instance, P2X7R in SGCs promotes the release of proinflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta, and interleukin-6 (IL-6) (Arulkumaran et al, 2011 ). In HIV treatment-induced neuropathic models, SGCs demonstrate increased GFAP expression and P2Y212 receptor activation (Zhou et al, 2019 ).…”

The Actions and Mechanisms of P2X7R and p38 MAPK Activation in Mediating Bortezomib-Induced Neuropathic Pain

“…The key step of p38MAPK phosphorylation in the central nervous system [ 7 , 8 ] and peripheral nervous system [ 9 – 11 ] in mediating neuroinflammation and resulting in neuropathic pain has been approached recently in several studies. The importance of the involvement of p38MAPK phosphorylation in the development and maintenance of neuropathic pain boosts us to explore the association of p38MAPK phosphorylation and P2X7R activation in mediating BTZ-induced neuropathic pain.…”

“…The importance of the involvement of p38MAPK phosphorylation in the development and maintenance of neuropathic pain boosts us to explore the association of p38MAPK phosphorylation and P2X7R activation in mediating BTZ-induced neuropathic pain. P2X7R has a crucial function in chronic pain or neuropathic pain in different pathological conditions, making P2X7R an appealing target for the treatment of intractable neuropathic pain [ 9 , 17 , 21 , 42 – 44 ]. Exploring the expression and activation of P2X7R in DRG and SDH is particularly important for finding novel targets for relieving BTZ-induced neuropathic pain.…”

“…P2X7R is located in microglia of the central nervous system and in SGCs of the DRG [15,16]. Activation of P2X7R in microglia of the spinal cord and in SGCs of DRG contributes to inflammatory pain [9,17].…”

“…It leads to the induction and expansion of neuropathic pain status. p38MAPK phosphorylation in the central nervous system [ 7 , 8 ] and peripheral nervous system [ 9 – 11 ] is closely correlated with neuroinflammation and neuropathic pain.…”